Deck 14: Solutions and Their Behavior

Question 1

What is the mole fraction of calcium chloride in 3.35 m CaCl₂(aq)? The molar mass of CaCl₂ is 111.0 g/mol and the molar mass of water is 18.02 g/mol.

A) 0.000866
B) 0.0569
C) 0.271
D) 37.2
E) 59.2

Answer 1

0.0569

Question 2

What is the definition of molality?

A) moles of solute per kg of solvent
B) grams of solute per kg of solution
C) grams of solute per liter of solution
D) moles of solute per liter of solvent
E) moles of solute per liter of solution

Answer 2

moles of solute per kg of solvent

Question 3

A concentrated sodium hydroxide solution is 50.5% NaOH by mass and has a density of 1.53 g/mL at 25°C.What is the molarity of NaOH?

A) 19.3 M
B) 0.0612 M
C) 8.25 M
D) 12.1 M
E) 0.0825 M

Answer 3

19.3 M

Question 4

What is the mass percent of an aqueous sodium hydroxide solution in which the mole fraction of NaOH is 0.101?

A) 20.0%
B) 12.1%
C) 68.9%
D) 12.4%
E) 3.31%

Question 5

What is the mole fraction of urea,CO(NH₂)₂, in a solution prepared by dissolving 6.8 g of urea in 33.5 g of methanol,CH₃OH?

A) 0.83
B) 0.17
C) 0.098
D) 0.90
E) 0.28

Question 6

Concentrated sodium hydroxide is 19.4 M and has a density of 1.54 g/mL.What is the molality of concentrated NaOH?

A) 12.6 m
B) 19.8 m
C) 25.4 m
D) 29.9 m
E) 50.4 m

Question 7

Calculate the molarity of a solution of magnesium chloride with a concentration of 30.3 mg/mL.

A) 0.159 M
B) 3.14 M
C) 0.636 M
D) 0.507 M
E) 0.318 M

Question 8

What is the mole fraction of urea,CH₄N₂O,in an aqueous solution that is 54% urea by mass?

A) 0.26
B) 0.74
C) 0.54
D) 0.37
E) 0.80

Question 9

If 27.9 g LiCl is dissolved in 175 g H₂O,what is the weight percent of LiCl in the solution?

A) 0.376%
B) 6.78%
C) 13.8%
D) 15.9%
E) 19.0%

Question 10

What is the mass percent of an aqueous sodium hydroxide solution in which the molality of NaOH is 10.7 m?

A) 0.124%
B) 68.9%
C) 1.69%
D) 30.0%
E) 0.322%

Question 11

If the concentration of sodium carbonate in water is 12.8 ppm,what is the molarity of Na₂CO₃(aq)? The molar mass of Na₂CO₃ is 106.0 g/mol.Assume the density of the solution is 1.00 g/mL.

A) 8.28 $\times$ 10^-6 M
B) 1.21 $\times$ 10^-4 M
C) 1.36 $\times$ 10^-3 M
D) 0.136 M
E) 0.121 M

Question 12

A 12.0% sucrose solution by mass has a density of 1.05 g/cm³.What mass of sucrose is present in a 63.0-mL sample of this solution?

A) 7.94 g
B) 7.20 g
C) 0.126 g
D) 551 g
E) 7.56 g

Question 13

The volume of a 15.8% (by mass)solution is 146.4 mL.The density of the solution is 1.084 g/mL.What is the mass of solute in this solution?

A) 159 g
B) 25.1 g
C) 1004 g
D) 21.3 g
E) 134 g

Question 14

How many milliliters of 15.7 M H₂SO₄ are needed to prepare 600.0 mL of 0.10 M H₂SO₄?

A) 0.26 mL
B) 94 mL
C) 3.8 mL
D) 1.9 mL
E) 4.8 mL

Question 15

What mass of an aqueous 22.9% sodium chloride solution contains 99.5 g of water?

A) 129 g
B) 29.6 g
C) 0.500 g
D) 22.8 g
E) 99.5 g

Question 16

What volume of a 0.771 M solution of CaCl₂ contains 1.28 g of solute?

A) 66.8 mL
B) 15.0 mL
C) 1.66 mL
D) 8.89 mL
E) 85.0 mL

Question 17

If 11.2 g of naphthalene,C₁₀H₈,is dissolved in 105.4 g of chloroform,CHCl₃,what is the molality of the solution?

A) 0.0875 m
B) 12.7 m
C) 0.830 m
D) 0.0961 m
E) 0.0991 m

Question 18

What is the molality of ethanol,C₂H₅OH,in an aqueous solution that is 37.4% ethanol by mass?

A) 0.597 m
B) 0.0130 m
C) 13.0 m
D) 0.719 m
E) 93.0 m

Question 19

A concentrated hydrochloric acid solution has a density of 1.19 g/mL at 25°C and is 12.1 M.What is the percent by mass of HCl in the solution?

A) 37.1% HCl by mass
B) 1.02% HCl by mass
C) 0.980% HCl by mass
D) 2.80% HCl by mass
E) 30.6% HCl by mass

Question 20

What is the mass of H₂SO₄ in a 46.4-mL sample of concentrated sulfuric acid that has a density of 1.84 g/mL and consists of 98.3% H₂SO₄?

A) 45.6 g
B) 83.9 g
C) 3.90 g
D) 1.81 g
E) 24.8 g

Question 21

A 15 meter by 12 meter pool of water has a depth of 2.2 meters.What mass of silver ion is present in the reservoir if the concentration of silver ion is 0.14 ppm? (1 m³ = 1000 L; assume the density of the solution is 1.00 g/mL)

A) 5.5 $\times$ 10^-4 g
B) 5.5 $\times$ 10^-2 g
C) 0.55 g
D) 5.5 g
E) 55 g

Question 22

Which action(s)will decrease the equilibrium concentration of an inert gas (such as N₂)in water?
1)decreasing the temperature of the water
2)increasing the volume of water
3)decreasing the pressure of the gas above the liquid

A) 1 only
B) 2 only
C) 3 only
D) 1 and 3
E) 1,2,and 3

Question 23

Which of the following compounds is $\textbf{ not }$ miscible with water?

A) CH₃NH₂
B) CH₃COOH
C) CCl₄
D) CH₃CN
E) HOCH₂CH₂OH

Question 24

The Henry's law constant for O₂ in water at 25 ^$\circ$ C is 1.3 $\times$ 10^-3 mol/kg.bar.What partial pressure of O₂ (in atm)is necessary to achieve an equilibrium concentration of 2.9 $\times$ 10^-3 mol/kg O₂? (1 atm = 0.9869 bar)

A) 0.44 atm
B) 0.45 atm
C) 2.1 atm
D) 2.3 atm
E) 3.8 atm

Question 25

The lattice enthalpy of KF is -808 kJ/mol and the enthalpy of solution of KF is -17.7 kJ/mol.Calculate the enthalpy of hydration of KF(s).

A) -790.3 kJ/mol
B) -35.4 kJ/mol
C) -825.7 kJ/mol
D) 790.3 kJ/mol
E) 825.7 kJ/mol

Question 26

The solubility of 1-hexanol in water is 0.60 g per 100 g of water at 25°C.What is the maximum amount of 1-hexanol that will dissolve in 5.3 g of water at 25°C?

A) 0.032 g
B) 0.11 g
C) 0.60 g
D) 3.2 g
E) 0.0011 g

Question 27

The standard enthalpy of formation of RbF(s)is -557.7kJ/mol and the standard enthalpy of formation of RbF(aq,1 m)is -583.8 kJ/mol.Determine the enthalpy of solution of RbF and indicate whether the solution temperature will increase or decrease when RbF is dissolved in water.

A) -26.1 kJ/mol; increase
B) 26.1 kJ/mol; increase
C) -26.1 kJ/mol; decrease
D) +1141.5 kJ/mol; increase
E) -1141.5 kJ/mol; decrease

Question 28

Two nonpolar solvents,such as hexane and carbon tetrachloride,may be miscible even though the enthalpy of mixing of these liquids might be small.A reason that mixing occurs is that mixtures have a greater dispersal of energy relative to pure solvents.The tendency toward greater dispersal of energy is a thermodynamic function called ____.

A) entropy
B) enthalpy
C) saturation
D) adhesion
E) cohesion

Question 29

Which of the following statements is INCORRECT?

A) The solubility of a gas in water decreases with increasing temperature.
B) The solubility of a gas in water is proportional to the partial pressure of the gas above the water.
C) The dissolution of a gas in water is usually an exothermic process.
D) The relationship between the solubility of a gas and its partial pressure is known as Henry's law.
E) The solubility of a gas in water is inversely proportional to the molar mass of the gas.

Question 30

According to the National Institute of Standards webbook,the Henry's Law constant for N₂ gas is 0.00060 mol/kg.bar at 25 ^$\circ$ C What is the Henry's law constant in units of mol/kg.atm? (1 bar = 0.9869 atm; 1 atm = 760 mmHg)

A) mol/kg.atm
B) mol/kg.atm
C) mol/kg.atm
D) mol/kg.atm
E) mol/kg.atm

Question 31

Which of the following liquids will be miscible with water in any proportion: ethanol (CH₃CH₂OH),carbon tetrachloride (CCl₄),hexane (C₆H₁₄),and/or formic acid (HCO₂H)?

A) ethanol and carbon tetrachloride
B) carbon tetrachloride and hexane
C) ethanol and formic acid
D) ethanol,carbon tetrachloride,and benzene
E) carbon tetrachloride,and formic acid

Question 32

What mass of Zn(NO₃)₂ must be diluted to a mass of 1.00 kg with H₂O to prepare 97 ppm Zn²⁺(aq)?

A) 7.8 $\times$ 10^-6 g
B) 7.8 $\times$ 10^-3 g
C) 3.3 $\times$ 10^-2 g
D) 1.3 $\times$ 10^-1 g
E) 2.8 $\times$ 10^-1 g

Question 33

The Henry's law constant for N₂ in water at 25 ^$\circ$ C is 6.0 $\times$ 10^-4 mol/kg.bar.What is the equilibrium concentration of N₂ in water when the partial pressure of N₂ is 586 mm Hg? (760 mm Hg = 1 atm = 0.9869 bar)

A) 1.4 $\times$ 10^-9 M
B) 1.8 $\times$ 10^-5 M
C) 4.6 $\times$ 10^-4 M
D) 7.7 $\times$ 10^-4 M
E) 7.9 $\times$ 10^-4 M

Question 34

Which of the following statements concerning solubility is/are CORRECT?
1)Ionic compounds composed of Group 1A metal ions and halide ions,such as NaCl,are insoluble in nonpolar solvents.
2)The solubility of the halogens (Cl₂,Br₂,and I₂)in polar solvents is greater than their solubility in nonpolar solvents.
3)The solubility of polar molecules,such as sugar,in polar solvents is generally greater than their solubility in nonpolar solvents.

A) 1 only
B) 2 only
C) 3 only
D) 1 and 3
E) 1,2,and 3

Question 35

Which of the following favor(s)the solubility of an ionic solid in a liquid solvent?

A) a small magnitude of the lattice energy of the solute
B) a large magnitude of the solvation energy of the ions
C) a large polarity of the solvent
D) all of the above
E) none of the above

Question 36

Which of the following statements is/are CORRECT?
1)Solubility is defined as the concentration of solute in equilibrium with undissolved solute in a saturated solution.
2)If two liquids mix to an appreciable extent to form a solution,they are miscible.
3)If two liquids mix completely in any proportion to form a solution,the resulting solution is supersaturated.

A) 1 only
B) 2 only
C) 3 only
D) 1 and 2
E) 2 and 3

Question 37

The change in energy accompanying the process below is the ____ of MX.
MX(s) $\to$ M⁺(aq)+ X^-(aq)

A) enthalpy of hydration
B) enthalpy of solution
C) lattice energy
D) enthalpy of formation
E) electron attachment enthalpy

Question 38

Which process is accompanied by the change in energy known as the lattice enthalpy of RbCl?

A) Rb⁺(g)+ Cl^-(g) $\to$ Rb⁺(aq)+ Cl^-(aq)
B) RbCl(s) $\to$ RbCl(aq,1 m)
C) Rb⁺(g)+ Cl^-(g) $\to$ RbCl(s)
D) Rb(s)+ Cl₂(g) $\to$ RbCl(s)
E) Rb(s)+ Cl₂(g) $\to$ RbCl(aq,1 m)

Question 39

What concentration of silver nitrate (in ppm)is present in 7.1 $\times$ 10^-7 M AgNO₃(aq)? For very dilute aqueous solutions,you can assume the solution's density is 1.0 g/mL.The molar mass of AgNO₃ is 169.9 g/mol.

A) 0.0071 ppm
B) 0.12 ppm
C) 0.71 ppm
D) 1.7 ppm
E) 8.3 ppm

Question 40

At a particular temperature the solubility of O₂ in water is 0.590 g/L at an oxygen pressure of 15.2 atm.What is the Henry's law constant for O₂?

A) 3.88 $\times$ 10^-2 L·atm/mol
B) 8.24 $\times$ 10² L·atm/mol
C) 2.80 $\times$ 10^-1 L·atm/mol
D) 1.21 $\times$ 10^-3 L·atm/mol
E) None of the above.

Question 41

What is the freezing point of an aqueous 1.36 m NaCl solution? (K_fp for water is 1.858°C/m.)Assume no ion pairing occurs.

A) 5.1°C
B) 2.5°C
C) -5.1°C
D) 0.0°C
E) -2.5°C

Question 42

The vapor pressure of pure water at 15 ^$\circ$ C is 12.8 mm Hg.What is the equilibrium vapor pressure of water above a mixture of 72.0 g ethanol (CH₃CH₂OH,molar mass = 46.07 g/mol)and 22.0 g water?

A) 2.84 mm Hg
B) 5.61 mm Hg
C) 7.19 mm Hg
D) 10.0 mm Hg
E) 12.8 mm Hg

Question 43

What mass of ethylene glycol,when mixed with 225 g H₂O,will reduce the equilibrium vapor pressure of H₂O from 1.00 atm to 0.800 atm at 100 ^$\circ$ C? The molar masses of water and ethylene glycol are 18.02 g/mol and 62.07 g/mol,respectively.Assume ideal behavior for the solution.

A) 15.6 g
B) 49.9 g
C) 194 g
D) 969 g
E) 3.10 $\times$ 10³ g

Question 44

Assuming ideal behavior,which of the following aqueous solutions would be expected to exhibit the $\underline{\text{ smallest}}$ freezing-point lowering?

A) 0.1 m KCl
B) 0.05 m CH₃COOH
C) 0.05 m Al₂(SO₄)₃
D) 0.1 m CaCl₂
E) 0.25 m C₆H₁₂O₆

Question 45

A solution consisting of 0.228 mol of methylbenzene,C₆H₅CH₃,in 255 g of nitrobenzene,C₆H₅NO₂,freezes at -0.3°C.Pure nitrobenzene freezes at 6.0°C.What is the freezing-point depression constant of nitrobenzene?

A) 1.1°C/m
B) 27°C/m
C) 14.0°C/m
D) 3.5°C/m
E) 7.0°C/m

Question 46

What is the equilibrium partial pressure of water vapor above a mixture of 37.5 g H₂O and 62.5 g HOCH₂CH₂OH at 55 ^$\circ$ C.The partial pressure of pure water at 55.0 ^$\circ$ C is 118.0 mm Hg.Assume ideal behavior for the solution.

A) 3.54 mm Hg
B) 31.7 mm Hg
C) 38.5 mm Hg
D) 79.5 mm Hg
E) 175 mm Hg

Question 47

If the solubility of O₂ at 0.360 bar and 25 ^$\circ$ C is 15.0 g/100 g H₂O,what is the solubility of O₂ at a pressure of 1.72 bar and 25 ^$\circ$ C?

A) 71.7 g/100 g H₂O
B) 24.2 g/100 g H₂O
C) 0.319 g/100 g H₂O
D) 0.0140 g/100 g H₂O
E) 3.14 g/100 g H₂O

Question 48

For the following gas-liquid equilibrium for an aqueous system at a constant partial pressure of O₂,
O₂(g) $\leftrightarrows$ O₂(aq)
What is the effect on the equilibrium composition of the liquid when the $\underline{\text{ temperature }}$ of the liquid is decreased?

A) The amount of O₂ dissolved in the liquid decreases.
B) The amount of O₂ dissolved in the liquid increases.
C) The amount of O₂ dissolved in the liquid does not change.
D) Not enough information is provided to answer the question.
E) Either A or B could occur.

Question 49

Henry's Law constant is 0.034 mol/kg.bar and 0.0013 mol/kg.bar for CO₂ and O₂ respectively at 25 ^$\circ$ C.What pressure of O₂ is required to achieve the same solubility as 0.218 bar of CO₂?

A) 5.7 bar
B) 0.0083 bar
C) bar
D) bar
E) 0.18 bar

Question 50

Assuming ideal behavior,which of the following aqueous solutions should have the highest boiling point?

A) 1.00 m LiBr
B) 0.75 m K₂SO₄
C) 0.50 m Ca(NO₃)₂
D) 0.75 m NaCl
E) 1.25 m C₆H₁₂O₆

Question 51

What is the freezing point of a 0.24 m solution of glucose,C₆H₁₂O₆,in water? (K_fp for water is 1.858°C/m.)

A) 0.22°C
B) 0.45°C
C) -0.45°C
D) -0.22°C
E) -0.89°C

Question 52

If a 25.0-g sample of a nonelectrolyte is dissolved in 145.0 g of water,the resulting solution will freeze at -0.89°C.What is the molar mass of the nonelectrolyte? (K_fp for water is 1.858°C/m.)

A) 76 g/mol
B) 0.36 g/mol
C) 990 g/mol
D) 290 g/mol
E) 360 g/mol

Question 53

What is the boiling-point $\underline{\text{ change }}$ for a solution containing 0.432 mol of naphthalene (a nonvolatile,nonionizing compound)in 250.g of liquid benzene? (K_bp = 2.53°C/m for benzene)

A) 4.37 °C
B) 5.86 °C
C) 0.273 °C
D) 1.46 °C
E) 1.093 °C

Question 54

The vapor pressure of water at 90°C is 0.692 atm.What is the vapor pressure (in atm)of a solution made by dissolving 1.28 mole(s)of CsF(s)in 1.00 kg of water? Assume that Raoult's law applies.

A) 0.661 atm
B) 0.676 atm
C) 0.692 atm
D) 0.724 atm
E) none of these

Question 55

What partial pressure of oxygen gas is required in order for 0.00392 g of the gas to dissolve in 23.7 mL of pure water? The Henry's law constant for oxygen gas is 1.3 $\times$ 10^-3 M atm^-1.

A) 2.2 $\times$ 10^-7 atm
B) 4.0 $\times$ 10⁰ atm
C) 1.6 $\times$ 10^-7 atm
D) 2.5 $\times$ 10^-1 atm
E) 4.2 $\times$ 10^-2 atm

Question 56

What mass of Na₂SO₄ must be dissolved in 100.0 grams of water to lower the freezing point by 2.50 ^$\circ$ C? The freezing point depression constant,K_fp,of water is -1.86 ^$\circ$ C/m.Assume the van't Hoff factor for Na₂SO₄ is 2.85.

A) 3.77 g
B) 6.36 g
C) 6.70 g
D) 11.3 g
E) 19.1 g

Question 57

What is the vapor pressure at 20°C of an ideal solution prepared by the addition of 4.60 g of the nonvolatile solute urea,CO(NH₂)₂,to 50.2 g of methanol,CH₃OH? The vapor pressure of pure methanol at 20°C is 89.0 mmHg.

A) 4.15 mmHg
B) 76.0 mmHg
C) 81.5 mmHg
D) 84.9 mmHg
E) 13.0 mmHg

Question 58

Ideally,colligative properties depend only on the

A) relative numbers of solute and solvent particles in a solution.
B) molar masses of the solute particles in a solution.
C) density of a solution.
D) hydrated radii of the molecules or ions dissolved in a solution.
E) partial pressure of the gases above the surface of a solution.

Question 59

For the following gas-aqueous liquid equilibrium for a closed system at a constant temperature,
O₂(g) $\leftrightarrows$ O₂(aq)
What is the effect on the equilibrium composition of the liquid when the $\underline{\text{ partial pressure }}$ of O₂ gas above the liquid is decreased?

A) The amount of O₂ dissolved in the liquid decreases.
B) The amount of O₂ dissolved in the liquid increases.
C) The amount of O₂ dissolved in the liquid does not change.
D) Not enough information is provided to answer the question.
E) Either A or B is possible.

Question 60

What is the freezing point of a solution containing 2.80 grams benzene (molar mass = 78.11 g/mol)dissolved in 43.0 grams paradichlorobenzene (molar mass = 147.0 g/mol)? The freezing point of pure paradichlorobenzene is 53.0 ^$\circ$ C and the freezing point depression constant,K_fp,is -7.10 ^$\circ$ C/m.

A) 46.7 ^$\circ$ C
B) 47.1 ^$\circ$ C
C) 58.9 ^$\circ$ C
D) 52.6 ^$\circ$ C
E) 58 .9 ^$\circ$ C

Question 61

Which of the following solutions would have the highest osmotic pressure?

A) 0.3 M C₆H₁₂O₆,glucose
B) 0.2 M MgBr₂,magnesium bromide
C) 0.2 M KCl,potassium chloride
D) 0.3 M CH₃COOH,acetic acid
E) 0.3 M C₁₂H₂₂O₁₁,sucrose

Question 62

All of the following are colloidal dispersions EXCEPT ____.

A) marshmallow
B) white wine
C) milk
D) whipped cream
E) cheese

Question 63

A surfactant used for cleaning is called a(n)________.

Question 64

Because ________ particles are relatively large (say,1000 nm in diameter)they scatter visible light,making the mixtures containing these particles appear cloudy.This scattering is known as the Tyndall effect.

Question 65

At 37°C,what is the osmotic pressure of a 0.59% NaCl by weight aqueous solution? Assume the density of the solution is 1.0 g/mL.Assume no ion pairing.(R = 0.0821 L · atm/K·mol)

A) 0.26 atm
B) 2.6 atm
C) 3.0 $\times$ 10² atm
D) 5.1 atm
E) 0.61 atm

Question 66

________ are colloidal dispersions of one liquid in another liquid.

Question 67

What type of colloid is formed when a solid is dispersed in a liquid?

A) foam
B) aerosol
C) sol
D) emulsion
E) gel

Question 68

Aqueous colloidal solutions can be classified as ________ (water-fearing),or hydrophilic (water-loving).

Question 69

If one of the factors determining the equilibrium of a system is changed,the system adjusts to counteract that change.This is known as ________ principle.

Question 70

The osmotic pressure of blood is 7.65 atm at 37 ^$\circ$ C.What mass of glucose (C₆H₁₂O₆,molar mass = 180.2 g/mol)is needed to prepare 2.25 L of solution for intravenous injection? The osmotic pressure of the glucose solution must equal the osmotic pressure of blood.(R = 0.08206 L.atm/mol.K)

A) 0.676 g
B) 0.698 g
C) 5.67 g
D) 122 g
E) 1.02 $\times$ 10³ g

Question 71

For a dilute solution of NH₄NO₃,the van't Hoff factor (i)would be approximately ___.

A) 1
B) 2
C) 3
D) 4
E) 5

Question 72

A 2.3-g sample of a small protein having a molecular weight of 62,000 g/mol is dissolved in 38.8 mL of water at 28°C.What is the osmotic pressure of the solution? (R = 0.0821 L · atm/K·mol; 1 atm = 760 mmHg)

A) 18 mmHg
B) 1100 mmHg
C) 1.7 mmHg
D) 32,000 mmHg
E) 0.024 mmHg

Question 73

A 0.20 M solution of MgSO₄ has an observed osmotic pressure of 7.7 atm at 25°C.Determine the observed van't Hoff factor for this experiment.

A) 2.0
B) 1.6
C) 0.31
D) 19
E) 1.8

Question 74

Colloids are described by all of the following $\textbf{ except: }$

A) The particles in a colloid are so small that settling is negligible.
B) The mixture appears cloudy.
C) Only combinations of liquids and gases can form colloids.
D) Colloids are not suspensions or homogeneous mixtures.
E) Mayonnaise,whipped cream and fog are all examples of colloids.

Question 75

Which of the following statements concerning osmosis is/are CORRECT?
1)Osmosis involves the movement of ions through a semipermeable membrane until the charges on both sides of the membrane are equal.
2)Solvents move from regions of low solute concentration to regions of higher solute concentration.
3)Osmotic pressure is a colligative property.

A) 1 only
B) 2 only
C) 3 only
D) 2 and 3
E) 1,2,and 3

Question 76

Which of the following solutions has the lowest osmotic pressure?

A) 0.10 M Al(NO₃)₃
B) 0.20 M NH₃
C) 0.15 M Ba(NO₂)₂
D) 0.10 M CaCl₂
E) 0.15 M NaCl

Question 77

A solution is prepared by dissolving 5.88 g of an unknown nonelectrolyte in enough water to make 0.355 L of solution.The osmotic pressure of the solution is 1.21 atm at 27 ^$\circ$ C.What is the molar mass of the solute? (R = 0.08206 L.atm/mol.K)

A) 0.00297 g/mol
B) 30.3 g/mol
C) 42.5 g/mol
D) 175 g/mol
E) 337 g/mol

Question 78

The following equation is known as ________ law:
.

Question 79

Which of the following statements about soaps and detergents is $\underline{\text{ false? }}$

A) The polar end is attracted to grease and oil.
B) They have a polar and a nonpolar end.
C) They are emulsifiers for grease and oil.
D) Phosphate detergents can produce pollution problems.
E) They can be described as surfactants.

Question 80

What concentration unit is used in the calculation of osmotic pressure for a dilute solution?

A) molality
B) weight percent
C) mass fraction
D) mole fraction
E) molarity